And like Einstein I personally believe that intelligence cannot be measured in the way that people are currently trying.

You can be fluent in a language and to a degree be intelligent because of your capacity to learn or you can be fluent in several languages but take thrice as long as the average person to learn and retain information. So the person that knows several languages might be perceived as the more intelligent one, but in fact the other is just uninterested, lazy or putting their energy into something else... For whatever reasons.